diff --git a/radar/2017-03-01/jest.md b/radar/2017-03-01/jest.md index b4e18a0..066ef64 100644 --- a/radar/2017-03-01/jest.md +++ b/radar/2017-03-01/jest.md @@ -1,6 +1,18 @@ --- title: "Jest" -ring: trial +ring: adopt quadrant: tools ---- \ No newline at end of file +--- +[Jest](https://facebook.github.io/jest/) is a javascript testing framework by facebook to test javascript code **and** react applications / components. + +We started using Jest (and [watchmen](https://github.com/facebook/watchman)) instead of Karma because it: + +- gives us integrated mocking library +- gives us integrated support for testing "promises" +- gives us integrated code coverage report +- automatically runs tests related to changed files (instead of all tests) +- gives us parallel test execution +- gives us snapshot testing for react components + +It is easy to set up. And even if you have a running setup with karma/chai you can easily replace karma with jest. With a small [workaround](https://medium.com/@RubenOostinga/combining-chai-and-jest-matchers-d12d1ffd0303#.3callo273), chai and jest test matchers work fine together.